Ruxolitinib

12.1 Mechanism of Action Ruxolitinib, a Janus kinase (JAK) inhibitor, inhibits JAK1 and JAK2 which mediate the signaling of a number of cytokines and growth factors that are important for hematopoiesis and immune function. JAK signaling involves recruitment of STATs (signal transducers and activators of transcription) to cytokine receptors, activation and subsequent localization of STATs to the nucleus leading to modulation of gene expression. The relevance of inhibition of specific JAK enzymes to therapeutic effectiveness is not currently known.

1 INDICATIONS AND USAGE OPZELURA is a Janus kinase (JAK) inhibitor indicated for: the topical short-term and non-continuous chronic treatment of mild to moderate atopic dermatitis in non-immunocompromised adult and pediatric patients 2 years of age and older whose disease is not adequately controlled with topical prescription therapies or when those therapies are not advisable. ( 1.1 ) the topical treatment of nonsegmental vitiligo in adult and pediatric patients 12 years of age and older. ( 1.2 ) Limitations of Use Use of OPZELURA in combination with therapeutic biologics, other JAK inhibitors or potent immunosuppressants such as azathioprine or cyclosporine is not recommended. ( 1.3 ) 1.1 Atopic Dermatitis OPZELURA is indicated for the topical short-term and non-continuous chronic treatment of mild to moderate atopic dermatitis in non-immunocompromised adult and pediatric patients 2 years of age and older whose disease is not adequately controlled with topical prescription therapies or when those therapies are not advisable. 1.2 Nonsegmental Vitiligo OPZELURA is indicated for the topical treatment of nonsegmental vitiligo in adult and pediatric patients 12 years of age and older. 1.3 Limitations of Use Use of OPZELURA in combination with therapeutic biologics, other Janus kinase (JAK) inhibitors, or potent immunosuppressants such as azathioprine or cyclosporine is not recommended.

2 DOSAGE AND ADMINISTRATION Atopic Dermatitis Apply a thin layer of OPZELURA topically twice daily to affected areas of up to 20% body surface area. ( 2.1 ) Do not use OPZELURA with occlusive dressings. ( 2.1 ) Adult and Pediatric Patients 12 Years of Age and Older Do not use more than one 60 gram tube of OPZELURA per week or one 100 gram tube per 2 weeks. ( 2.1 ) Pediatric Patients 2 to 11 Years of Age Do not use more than one 60 gram tube of OPZELURA per 2 weeks. ( 2.1 ) Nonsegmental Vitiligo Apply a thin layer of OPZELURA topically twice daily to affected areas of up to 10% body surface area. ( 2.2 ) Do not use more than one 60 gram tube of OPZELURA per week or one 100 gram tube per 2 weeks. ( 2.2 ) 2.1 Recommended Dosage and Administration for Atopic Dermatitis OPZELURA is for topical use only. OPZELURA is not for ophthalmic, oral, or intravaginal use. Instruct patients to apply a thin layer of OPZELURA twice daily to affected areas of up to 20% body surface area. Do not use OPZELURA with occlusive dressings. Stop using when signs and symptoms (e.g., itch, rash, and redness) of atopic dermatitis resolve. If signs and symptoms do not improve within 8 weeks, patients should be re-examined by their healthcare provider [see Clinical Studies ( 14.1 )] . Adult and Pediatric Patients 12 Years of Age and Older Do not use more than one 60 gram tube of OPZELURA per week or one 100 gram tube per 2 weeks. Pediatric Patients 2 to 11 Years of Age Do not use more than one 60 gram tube of OPZELURA per 2 weeks. 2.2 Recommended Dosage and Administration for Nonsegmental Vitiligo OPZELURA is for topical use only. OPZELURA is not for ophthalmic, oral, or intravaginal use. Instruct patients to apply a thin layer of OPZELURA twice daily to affected areas of up to 10% body surface area. Do not use more than one 60 gram tube of OPZELURA per week or one 100 gram tube per 2 weeks. Satisfactory patient response may require treatment with OPZELURA for more than 24 weeks. If the patient does not find the repigmentation meaningful by 24 weeks, the patient should be re‑evaluated by the healthcare provider [see Clinical Studies ( 14.2 )] .

6 ADVERSE REACTIONS In atopic dermatitis, the most common adverse reactions (incidence ≥ 1%) are nasopharyngitis, diarrhea, bronchitis, ear infection, eosinophil count increased, urticaria, folliculitis, tonsillitis, rhinorrhea, upper respiratory tract infection, COVID-19, application site reactions, pyrexia, and white blood cell decreased. ( 6 ) In nonsegmental vitiligo, the most common adverse reactions (incidence ≥ 1%) are application site acne, application site pruritus, nasopharyngitis, headache, urinary tract infection, application site erythema, and pyrexia. ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact Incyte Corporation at 1-855-463-3463 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. Adverse Reactions in Adult and Pediatric Subjects 2 Years of Age and Older with Atopic Dermatitis Adult and Pediatric Subjects 12 Years of Age and Older In two double-blind, vehicle-controlled clinical trials (TRuE-AD1 and TRuE-AD2), 499 adult and pediatric subjects 12 years of age and older with atopic dermatitis were treated topically with OPZELURA twice daily for 8 weeks [see Clinical Studies ( 14.1 )] . The adverse reactions reported by ≥ 1% of OPZELURA treated subjects and at a greater incidence than in the vehicle arm are listed in Table 1. Table 1: Adverse Reactions Occurring in ≥ 1% of Adult and Pediatric Subjects 12 Years of Age and Older Treated with OPZELURA for Atopic Dermatitis through Week 8 in TRuE-AD1 and TRuE-AD2 Adverse Reaction OPZELURA (N = 499) n (%) Vehicle (N = 250) n (%) Nasopharyngitis 13 (3) 2 (1) Bronchitis 4 (1) 0 (0) Ear infection 4 (1) 0 (0) Eosinophil count increased 4 (1) 0 (0) Urticaria 4 (1) 0 (0) Diarrhea 3 (1) 1 (< 1) Folliculitis 3 (1) 0 (0) Tonsillitis 3 (1) 0 (0) Rhinorrhea 3 (1) 1 (< 1) Adverse reactions that occurred in TRuE-AD1 and TRuE-AD2 in < 1% of subjects in the OPZELURA group and none in the vehicle group were: neutropenia, allergic conjunctivitis, pyrexia, seasonal allergy, herpes zoster, otitis externa, Staphylococcal infection, and acneiform dermatitis. No clinically meaningful differences in safety or effectiveness were observed between adult and pediatric subjects 12 to 17 years of age. Pediatric Subjects 2 to 11 Years of Age In a double-blind, vehicle-controlled clinical trial (TRuE-AD3), 130 pediatric subjects 2 to 11 years of age with mild to moderate atopic dermatitis were treated topically with OPZELURA twice daily for 8 weeks [see Clinical Studies ( 14.1 )] . The adverse reactions reported by ≥ 1% of subjects treated with OPZELURA and at a greater incidence than in the vehicle arm are listed in Table 2. Table 2: Adverse Reactions Occurring in ≥ 1% Pediatric Subjects 2 to 11 Years of Age Treated with OPZELURA for Atopic Dermatitis through Week 8 in TRuE-AD3 Adverse Reaction OPZELURA (N = 130) n (%) Vehicle (N = 65) n (%) Upper respiratory tract infection Upper respiratory tract infection includes upper respiratory tract infection, nasopharyngitis, rhinorrhea, oropharyngeal pain, respiratory tract congestion, viral upper respiratory tract infection 20 (15) 7 (11) COVID-19 6 (5) 2 (3) Application site reaction Application site reaction includes application site pain, application site irritation, application site discomfort, application site pruritus 6 (5) 1 (2) Pyrexia 3 (2) 0 (0) White blood cell decreased White blood cell decreased includes white blood cell decreased, leukopenia 2 (2) 0 (0) Subjects with cytopenias (defined as hemoglobin < 10 g/dL, absolute neutrophil count (ANC) < 1000/μL, and platelet count < 100,000/μL) at screening were excluded from the trial. The impact of OPZELURA on blood cell counts in this population has not been studied. Adverse Reactions in Adult and Pediatric Subjects 12 Years of Age and Older with Nonsegmental Vitiligo In two double-blind, vehicle-controlled clinical trials (TRuE-V1 and TRuE-V2), 449 adult and pediatric subjects 12 years of age and older with nonsegmental vitiligo were treated topically with OPZELURA twice daily for 24 weeks [see Clinical Studies ( 14.2 )] . The adverse reactions reported by OPZELURA treated subjects with an incidence of ≥ 1% and at least 1% greater incidence than in the vehicle arm in the 24-week double-blind period are listed in Table 3. Table 3: Adverse Reactions Occurring in ≥ 1% of Adult and Pediatric Subjects 12 Years of Age and Older Treated with OPZELURA for Nonsegmental Vitiligo through Week 24 in TRuE-V1 and TRuE-V2 Adverse Reaction OPZELURA (N = 449) n (%) Vehicle (N = 224) n (%) Application site acne 26 (6) 2 (1) Application site pruritus 23 (5) 6 (3) Nasopharyngitis 19 (4) 5 (2) Headache 17 (4) 6 (3) Urinary tract infection 7 (2) 1 (< 1) Application site erythema 7 (2) 1 (< 1) Pyrexia

7 DRUG INTERACTIONS Drug interaction studies with OPZELURA have not been conducted. Ruxolitinib is known to be a substrate for cytochrome P450 3A4 (CYP3A4). Inhibitors of CYP3A4 may increase ruxolitinib systemic concentrations whereas inducers of CYP3A4 may decrease ruxolitinib systemic concentrations [see Clinical Pharmacology ( 12.3 )] . Strong Inhibitors of CYP3A4 Avoid concomitant use of OPZELURA with strong inhibitors of CYP3A4 as there is a potential to increase the systemic exposure of ruxolitinib and could increase the risk of OPZELURA adverse reactions [see Clinical Pharmacology ( 12.3 )] .